Everyday, my 18 months old boy is always asking to watch a movie by coming to my laptop and requesting to watch movie by talking with his baby talk style. I have a good serial cartoon movies for him. But sometimes he feel bored with the same movies which I chosed for him.

Before I am going further, actually, can my 18 months old boy learn from watching movies? If it is yes, do you have any recommended movies which has good contents for my boy to learn?

So at the most basic, no, your 18 month old son is unlikely to learn anything from watching a movie, and probably will have a hard time sitting through most of it, let alone the whole thing.

What I've found to be a better alternative is to explore short video clips that address specific interests or questions your child may have. My son loves animals, and sometimes questions come up about animals (such as "what does a toucan sound like?") that can be answered by a quick youtube.com video. Let your son drive the topics by telling you what he's interested in, then you find a short video or two to show him about what he's asking about. Their attention span is short enough that he'll likely come up with a different topic to look up pretty quickly, and he'll learn a lot more just by interacting with you while you look up the videos and talk about what you're watching.

I see so there is no evidence that TV will give benefits. But in reality, sometime I found him laughing when watching the movie and also copycat the act of the cartoon like toasting or jumping. Sometimes also he is trying to hide behind me if some weird sound is came out from the cartoon movies. Does it mean he learn something from the movie?
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kalinggaApr 17 '13 at 3:57

@kalingga I'd say hiding from a strange noise is not the same thing as learning. To quote from my other answer: "while there is conflicting information on whether or not they can learn anything useful from television, even the studies that show some learning indicate that the learning is less than would be obtained from comparable 'live' interactions." So yes, it is possible that he may be learning something, but it is almost certain that whatever learning is happening is inefficient and slow compared to what he'd get from direct interactions with you.
–
BeofettApr 17 '13 at 12:11

The American Academy of Pediatrician's policy statement addresses this very issue. You can read it in full here.

In fact, 2 studies have found
that watching a program such as “Sesame
Street” has a negative effect on
language for children younger than 2
years, and 2 studies have found no
evidence of benefit....Children 12 to 18
months of age are more likely to learn
from a live presentation than from a
televised one and are also more likely
to remember the information from a
live presentation afterward....Some 18- to 24-month-olds
might be capable of learning from media,
but others might not. Other variables
that influence a child’s ability to
learn are the content of the program,
the amount of television watched, and
whether a parent is watching with the
child.

Rather than screen time, the AAP recommends:

Unstructured playtime is more
valuable for the developing brain
than any electronic media exposure.
If a parent is not able to actively
play with a child, that child
should have solo playtime with an
adult nearby. Even for infants as
young as 4 months of age, solo play
allows a child to think creatively,
problem-solve, and accomplish
tasks with minimal parent interaction.
The parent can also learn
something in the process of giving
the child an opportunity to entertain
himself or herself while remaining
nearby.

I realize this is highly subjective and only a single anecdote regarding language skills but...

We let both our children watch animated movies from a rather early age while a friend of ours was very strict with limiting their kids' screen time. We regularly gets comments on how well our children are developed verbally while our friends kids can barely be understood well into an age that they should be. I've also never been a parent to use much baby talk with our kids. I let a few cute things slide past now and then but for the most part I speak to my kids using proper language and I think that has helped them develop better language skills faster. I believe that having the language skills early on will naturally encourage learning since they'll be able to absorb what's going on around them because they understand it

I pretty much agree with everyone elses answer (screen at the youngest ages is a waste of valuable awake time) I read the well research "Screen Time" expecting the conventional message and found a balanced conclusion that TV that is age inappropriate is really bad, but TV that is age appropriate is at least not bad.

At the youngest ages, pretty much only Sesame Street, Dora the Explorer are age appropriate. (At younger than that, you are just using the flashing lights to hypnotize them so you can set them down and do something that requires two hands-- this is esp true for the Baby Einstein)

Also, what counts at age appropriate can be surprising. I used this website to re-callibrate what I thought was age-appropriate- http://www.commonsensemedia.org/ Previously I consistently underestimated the age at which something become age appropriate. It's a pity my son will have to wait so long to see his first Sci-Fi movie. (8 and 9+ for things like Lost in Space, The Black Hole or Star Wars)

I read somewhere (*) that screen time (including TV, video games, smartphones, tablets ...) should be limited to 1 hour/week/year of the kid (so 3h/week for a 3 years old).

According to several links on the internet, it is considered a bad idea for the kid's helath to start watching TV or before 2.

From my personal experience, we started showing very short (5 - 15 min max) cartoons to my daughter around the age of 2, such as Pixar or Disney short movies like you can find on Youtube. No more than 10-15 min a few times a week. We always watch together with her and comment, point out the animals or explain the situations.

She really enjoys these movies and sometimes refers to scenes she saw in other situations.
So I think she is understanding some of it and learning a bit. But the main purpose for us is to entertain her.